Tag Archives: telephoto

The Big Fix

Photo made with Nikon D610 and Nikkor 200-500mm f/5.6E at 500mm, f/16, ISO 100, 1/250-second

Photo made with Nikon D610 and Nikkor 200-500mm f/5.6E at 500mm, f/16, ISO 100, 1/250-second

I can clearly recall the exact moment when I realized there was a problem with my Nikon 200-500mm, f/5.6E telephoto zoom lens. It was on the afternoon of Wednesday, November 11, 2015. I had the day off from work and was setting up in the backyard to make some test photos demonstrating the effectiveness of the new lens’s vibration reduction (VR) feature. It was the above photo that caught my eye and started me down a challenging, sometimes frustrating road that would take nearly six weeks to complete. I’m some respects, I’m still on that road.

The above image caught my attention because it is so obviously overexposed. It was also totally unexpected. I had been using a hula dancer toy as a photographic subject to test the vibration VR of the 200-500mm lens. Reviewing the rest of the images in the sequence, the image shot at f/5.6 appeared to be properly exposed but the images made at f/8 and higher were overexposed. It also appeared that the degree of overexposure increased in proportion to the increase in f-stop setting used. The above image was made with a setting of f/16 and is about 2 stops overexposed.

In a nutshell, what I had discovered was that my Nikon D610 camera body was not able to control the electromagnetic diaphragm of the 200-500mm lens. The diaphragm determines the aperture of the lens, which controls the amount of light hitting the sensor. Lens aperture (f-stop) along with ISO and shutter speed form what is commonly referred to as the exposure triangle. A compatible trio of settings produces a properly-exposed image. If one of the settings is off, the resulting image will look either over- or underexposed.

That same day, I called Nikon USA’s service and support line and spoke with a call center agent. I described the problem and, ultimately, was advised to send in the lens for evaluation. Just a month earlier in October 2015, I had shipped the lens to Nikon for a firmware upgrade. The shipping and upgrade were covered under warranty for that service center visit. The UPS charge for this shipment would come out of my pocket.

The lens went out via UPS on Wednesday, November 11 and arrived at Nikon’s Los Angeles service center on Friday, November 13. (I chose not to take that as an omen.) The following Monday, November 16, I received an email from Nikon with an estimate for service to the lens. Nikon intended to address the problem with a firmware upgrade, which would be covered under warranty. After reading this, I contacted Nikon via their online service and support site, asking if this was the same firmware upgrade which had already been performed, a month earlier. The email reply to my query read, “Thank you for contacting Nikon. This is covered under warranty and this is the appropriate firmware update. If you have questions or concerns, please call or e-mail us.”

Well, OK then.

The upgrade was done and the lens shipped back at Nikon’s expense, arriving via UPS on November 23. It didn’t take more than a couple of minutes to confirm that the firmware upgrade had done nothing to correct the problem. To more fully document this issue, I made a series of exposures of my favorite test subject to demonstrate the increasing degree of overexposure at larger f-stop settings. Below, are several of the images I uploaded to the Nikon USA service center site for a technician to review.

Photo made with Nikon D610 and Nikkor 200-500mm f/5.6E at 300mm, f/5.6, ISO 100, 1/640-second

Photo made with Nikon D610 and Nikkor 200-500mm f/5.6E at 300mm, f/5.6, ISO 100, 1/640-second

Photo made with Nikon D610 and Nikkor 200-500mm f/5.6E at 300mm, f/8, ISO 100, 1/400-second

Photo made with Nikon D610 and Nikkor 200-500mm f/5.6E at 300mm, f/8, ISO 100, 1/400-second

Photo made with Nikon D610 and Nikkor 200-500mm f/5.6E at 300mm, f/11, ISO 100, 1/200-second

Photo made with Nikon D610 and Nikkor 200-500mm f/5.6E at 300mm, f/11, ISO 100, 1/200-second

Photo made with Nikon D610 and Nikkor 200-500mm f/5.6E at 300mm, f/16, ISO 100, 1/100-second

Photo made with Nikon D610 and Nikkor 200-500mm f/5.6E at 300mm, f/16, ISO 100, 1/100-second

Tuesday, November 24, I had another phone conversation with a call center agent. I again described the problem and explained that it appeared my Nikon D610 camera was unable to control the lens’s electromagnetic diaphragm. I also shared that I’d made test exposures with four other F-mount lenses: the Nikkor 16-35mm f/4, Tamron 24-70mm f/2.8 VC, Tamron 70-200mm f/2.8 VC and Nikkor 70-300mm f/4.5-5.6. There was no overexposure problem with these lenses and it appeared the problem was isolated just to the 200-500mm f/5.6E lens.

The day before Thanksgiving, November 25, I received an email from a Nikon technician who’d reviewed the above images. In his message, the technician asked that I ship both the D610 camera and the 200-500mm lens for evaluation and possible service. A UPS shipping label was attached. As reluctant as I was to be without my primary camera and the new lens, I wanted to get the problem resolved as quickly as possible. So, I boxed up the D610 and lens, drove to the nearest UPS shipping center and sent my babies off to LA for some TLC.

December was a long month. I had the privilege of serving on a jury for a criminal trial the first week of the month. Several major work projects were due for completion over the next two weeks and I would be traveling with family for the holidays, beginning December 22. Needless to say, I was anxious to have the camera and lens back, both in good working order, in time for the family trip to California. The month was further disrupted when I received news that a close high school friend had passed away. Travel to the Midwest for the funeral took out of town for several days.

I arrived home the afternoon of Sunday, December 20 to find two packages from Nikon sitting on the dining room table. One, was my D610 camera. The other, was my 200-500mm lens. After unpacking my suitcase and getting settled, I fetched a cutting tool from our kitchen utility drawer and opened the packages. A few minutes later, the 200-500 was firmly affixed to the D610 and ready to make images.

To my great relief, the camera and lens made properly-exposed images at a range of apertures. It appeared that Nikon had successfully repaired the problem. What repairs did they make? It’s not entirely clear but, according to the packing slip accompanying the lens, Nikon did the following work:

  • Repaired aperture operation
  • Replaced diaphragm and ring
  • Replaced a lens group
  • Adjusted aperture operation
  • Checked focus and VR operation.
  • Did a general exam and cleaning of the lens

My D610 camera body was also evaluated and found to be in good working order. It was checked and cleaned before return shipment.

Since receiving the repaired lens back from Nikon and during trips to California and New Mexico, I’ve made nearly 3,500 exposures at a range of apertures from f/5.6 to f/16. All appear to be correctly exposed. Below, are a few samples.

White-tailed Kite. Photo made with Nikon D610 and Nikkor 200-500mm f/5.6E at 500mm, f/8, ISO 500, 1/2000-second

White-tailed Kite. Photo made with Nikon D610 and Nikkor 200-500mm f/5.6E at 500mm, f/8, ISO 500, 1/2000-second

Alcatraz. Panoramic stitch made with Nikon D610 and Nikkor 200-500mm f/5.6E at 500mm, f/10, ISO 800, 1/2000-second

Alcatraz. Panoramic stitch made with Nikon D610 and Nikkor 200-500mm f/5.6E at 200mm, f/10, ISO 800, 1/2000-second

Javelina on parade. Photo made with Nikon D610 and Nikkor 200-500mm f/5.6E at 500mm, f/13, ISO 4500, 1/200-second

Javelina on parade. Photo made with Nikon D610 and Nikkor 200-500mm f/5.6E at 500mm, f/13, ISO 4500, 1/200-second

Eagles on ice. Photo made with Nikon D610 and Nikkor 200-500mm f/5.6E at 500mm, f/16, ISO 640, 1/250-second

Eagles on ice. Photo made with Nikon D610 and Nikkor 200-500mm f/5.6E at 500mm, f/16, ISO 640, 1/250-second

I am, of course, thrilled to have my lens back in good working order. Though some additional time is needed before I’ll have full confidence that the repair to the lens completely resolves the diaphragm-control problem, I have been extremely satisfied with the lens’s performance over the last several weeks. I also understand that equipment sometimes fails. That’s what warranties are for. I don’t fault Nikon for the mechanical failure to their product and am genuinely grateful that they addressed the problem in a forthright and timely manner.

I would like to take this opportunity to share some advice I’ve offered Nikon through email communication. In a nutshell, I’ve recommended Nikon update their service and support system to provide…

  • customers email updates about the status of their repair and estimated time of completion.
  • customers access to a Nikon technician who can explain in plain language the problem being addressed.
  • call center staff access to a customer database with detailed information about past and ongoing product service and repairs.

While I am satisfied with the outcome of this service and repair experience, there were times during those six weeks when the lack of information and the inability to communicate with a technically-proficient Nikon employee added to my level of frustration. The experience could have been made less stressful if I’d been provided regular updates on the status of my repair, had the opportunity to communicate by phone or instant messaging with a technician about the symptoms I was experiencing, and if I had not needed to explain the problem to four different call center staff members, none of whom appeared to have access to a detailed history of this particular repair.

I love using and doing photography with Nikon products and welcome the opportunity to remain a Nikon customer for many years to come. That said, their customer support could use some work. Whether you’re a Nikon employee, a fellow photographer or a friend, please take this blog entry in the spirit in which it is offered: an objective recounting of a recent customer service experience and an effort to provide constructive feedback to a company whose products I truly enjoy using.

Well, I’ve been rambling on about this far too long. It’s time for me to get out and shoot!

January 2016 | Bill Ferris

Nikon 200-500mm f/5.6E – Short Term Review

The Nikon AF-S 200-500mm f/5.6E ED VR Zoom Lens

The Nikon AF-S 200-500mm f/5.6E ED VR Zoom Lens (Bill Ferris)

In August 2015, Nikon announced three new lenses that would soon be available to the photographic community. Introduced that summer day were the AF-S 24-70mm f/2.8E ED VR, the AF-S 24mm f/1.8G ED and the AF-S 200-500mm f/5.6E ED VR.

The featured player of this trio was the eagerly anticipated refresh of Nikon’s well-regarded AF-S 24-70mm f/2.8G ED zoom lens. The 24-70 f/2.8G is a popular wide angle zoom among both professional and enthusiast photographers. It is considered by many wedding and portrait photographers to be among the Holy Trinity of fast Nikon zooms, including the 14-24mm f/2.8G ED and the 70-200mm f/2.8G ED VR II. The new lens, the AF-S 24-70mm f/2.8E ED VR features Nikon’s electronic aperture mechanism and also adds vibration reduction (VR) technology to the venerable optic.

The biggest surprise of the day – in more ways than one – was Nikon’s introduction of the AF-S 200-500mm f/5.6E ED VR telephoto zoom lens. What made this lens so surprising were its focal length range and price. Nikon and Canon are known around the world as the leading manufacturers of telephoto lenses for professionals and serious amateurs. From the 200mm f2 to the 800mm f/5.6, Nikon’s line of fast long focal length primes are coveted by sports, wildlife and action photographers. Two professional grade zooms, the AF-S 80-400mm f/4.5-5.6G ED VR and AF-S 200-400mm f/4G ED VR II, bring zoom flexibility to the system.

These are professional quality lenses and priced, accordingly. With a manufacturer’s suggested retail price of about $2,700 US, the 80-400mm f/4.5-5.6G is the least expensive of the bunch. The fast primes are priced at from $6,000 to $17,900 US. The 200-400mm f/4G weighs in at a hefty $7,000 US.

By contrast, the new 200-500mm f/5.6E is priced to be accessible to the consumer: just under $1,400 US. The zoom range and constant aperture suggest this lens was designed and released to compete directly with consumer-priced zooms manufactured by Tamron and Sigma. Tamron introduced the 150-600mm f/5-6.3 Di VC USD in November 2013. Priced at about $1,100 US, the Tamron 150-600 brought quality long telephoto zoom performance squarely within reach of the enthusiast photographer. While sports shooters balked at the relatively slow aperture range, wildlife photographers lined up to add this new lens to their arsenals.

Less than a year later in September 2014, Sigma entered the fray introducing two 150-600mm f/5-6.3 telephoto zooms. They were labeled “Contemporary” and “Sports.” The 150-600mm f/5-6.3 DG OS HSM Contemporary was introduced at about $1,100 US and had the Tamron zoom squarely in its sites. Though the highest priced of the trio at about $2,000 US, the Sigma 150-600 f/5-6.3 DG OS HSM Sports is still well under the entry level fee for a high end Nikon or Canon zoom.

I spent the better part of a year contemplating whether or not I should add one of these three lenses to my collection. My growing interest in sports and wildlife photography had created a need for more reach in my lens collection. The Tamron and Sigma zooms certainly addressed that interest. However, their relatively slow focal ratios introduced just enough hesitation that I never pulled the trigger to place an order. Then, Nikon’s August 2015 announcement happened.

Within 48-hours, I had done something that was a first for me: pre-ordered a lens. I’ve never been much of a first adopter of tech. Rather than live on the bleeding edge of consumer technologies, I generally prefer to stand back, observe and wait for good deals to emerge on established quality kit. The Nikon AF-S 200-500mm f/5.6E ED VR, however, is a different story.

The Nikon 200-500mm f/5.6E, Tamron 150-600 f/5-6.3 Di VC USD, Sigma 150-600 f/5-6.3 DG OS HSM Contemporary and Sports lenses are shown above in their comparative sizes.

The Nikon 200-500mm f/5.6E, Tamron 150-600 f/5-6.3 Di VC USD, Sigma 150-600 f/5-6.3 DG OS HSM Contemporary and Sports lenses are shown above in their comparative sizes.

I have to be honest, the Nikon name immediately intrigued me. I’m a Nikon shooter, having owned five Nikon camera bodies and numerous lenses over the last 25 years. When I placed the pre-order, I did so trusting that Nikon would deliver a quality product. Time will tell if that is the case.

Setting aside brand loyalty, there were several performance specifications that also caught my attention. The first and most immediate was the 200mm to 500mm focal length zoom range. At the short end this lens picks up where the excellent Tamron 70-200mm f/2.8 Di VC USD leaves off. At the long end of 500mm, the lens offers more than enough reach for quality sports photography and also for wildlife. The constant f/5.6 aperture through the full zoom range makes this lens a half-stop faster than the Tamron and Sigma zooms. It may not seem like much but that difference in light-gathering means my Nikon D610 camera should be able to use all 39 autofocus points at any focal length. At f/6.3, the D610 starts dropping the outermost AF points.

Another intriguing feature was the latest generation VR technology packaged with this lens. Nikon describes the 200-500 f/5.6E as being capable of delivering up to 4.5 stops of vibration reduction. The general rule of photography has, for generations, been that a photographer using good handholding technique should get sharp results using a shutter speed of 1/focal length. In the case of a 500mm lens, a 1/500-second exposure should not require VR. (This is not to say that VR would not aid a handheld exposure at that speed, merely that good handholding technique with a 500mm at 1/500-second should produce a sharp image.) A 4.5 stop improvement with VR translates to a minimum exposure time of between 1/20- and 1/30-second. That’s amazing!

An MTF chart showing the theoretical performance of the Nikon AF-S 200-500mm f/5.6E at 200mm f/5.6. (courtesy Nikon Corporation)

A Modulation Transfer Function (MTF) chart showing the theoretical performance of the Nikon AF-S 200-500mm f/5.6E at 200mm f/5.6. The industry standard practice is that MTF charts display computer-modeled performance characteristics based on lens design. (courtesy Nikon Corporation)

An MTF chart showing the theoretical performance of the Nikon AF-S 200-500mm f/5.6E at 500mm f/5.6. (courtesy Nikon Corporation)

A MTF chart showing the theoretical performance of the Nikon AF-S 200-500mm f/5.6E at 500mm f/5.6. (courtesy Nikon Corporation)

The above MTF (Modulation Transfer Function) charts illustrate the theoretical performance of the Nikon AF-S 200-500mm f/5.6E ED VR zoom lens. The top chart illustrates theoretical performance of the lens at 200mm f/5.6 while the bottom chart shows theoretical performance at 500mm f/5.6. Interpretations of MTF charts are always at least somewhat subjective. That said, I believe a reasonably objective translation would be as follows:

The red lines illustrate contrast performance while the blue lines illustrate resolution performance. The vertical scale measures performance in both areas with better performance being higher on the scale. The horizontal scale measures distance from the center of the lens. At 200mm f/5.6, the lens should deliver excellent contrast (0.9 or higher) across the entire angle of view. Resolution should also be excellent from the center to roughly two-thirds the distance to the edge of the angle of view. Very good resolution performance can be expected across much of the rest of the angle of view with good performance at the very edge. At 500mm, f/5.6, the lens continues to deliver excellent contrast performance across the full angle of view. The slight separation of the sagittal (solid) and meridional (dashed) lines suggests a subtle though largely imperceptible loss of contrast. Resolution performance continues to be excellent at 500mm, f/5.6 across half the angle of view and remains very good to the edge of the field. The separation of sagittal and meridional lines suggests a possible though subtle astigmatism. This lens should control for chromatic aberration, quite well.

The excellent theoretical performance of the lens was the deal-maker for me, giving real confidence in the decision to pre-order. Then, the waiting began.

The Nikon AF-S 200-500mm f/5.6E ED VR zoom lens fully extened to 500mm with the lens hood attached.

The Nikon AF-S 200-500mm f/5.6E ED VR zoom lens fully extended to 500mm with the lens hood attached. (Bill Ferris)

On the evening of September 23, UPS delivered my copy of the Nikon AF-S 200-500mm f/5.6E ED VR zoom lens. It was too late on that day to do much more than record an unboxing video for my YouTube channel and take a few photos of the new lens. A month has now passed during which time I have made a bit more than 2,600 exposures with the 200-500. What follows, is a Short Term Review based on the first month’s use. This isn’t a final review and, despite having formed some strong initial impressions, will not include any final conclusions. This review will include my initial observations about the performance of the lens and my own development as a photographer working at super telephoto ranges.

I’ll begin with the vital statistics:

  • Length at 200mm (no lens hood; no lens caps): 10 1/2″
  • Length at 200 mm (w/ lens hood): 14″
  • Length at 500mm (no lens hood; no lens caps: 13 1/2″
  • Length at 500mm (w/ lens hood): 17″
  • Diameter (front of lens): 4″
  • Circumference (front of lens): 13″
  • Diameter (front of lens with lens hood): 5 1/8″
  • Circumference (front of lens hood): 16 1/2″
  • Weight (w/ lens hood, lens caps, tripod collar): 5 lbs. 6.5 oz (86.5 oz.)
  • Weight (w/ lens hood, tripod collar): 5 lbs. 5.0 oz. (85.0 oz)
  • Weight (w/ tripod collar): 5 lbs. 1 oz. (81.0 oz)
  • Weight (w/ tripod collar and Oben mounting plate): 5 lbs. 2.5 oz (82.5 oz)
  • Weight of Lens only (no tripod collar, no lens hood, no lens caps): 4 lbs. 10.0 oz. (74.0 oz.)
  • Weight of tripod collar: 7.0 oz.
  • Lens Hood dimensions: 3 3/4″ length x 5 1/8″ diameter
  • Weight of lens hood: 4.0 oz.
Controls on the side of hte Nikon 200-500mm f/5.6E. (Bill Ferris)

Controls on the side of the Nikon 200-500mm f/5.6E. (Bill Ferris)

The left side of the lens is where you will find the various controls:

  • M/A – M: Autofocus switch. In M/A, lens autofocuses with instantaneous manual focus override as an available option. In M, the lens manually focuses, only.
  • FULL / ∞ to 6m: When focusing on subjects nearer than 6 meters (20 feet) distant, set to FULL. When focusing on subjects at greater than 6 meters distance, set to ∞ to 6m.
  • VR On / VR Off: Vibration Reduction (VR) On/Off switch. VR should not be turned on until camera body is on. VR should be turned off before camera body is turned off.
  • NORMAL / SPORT: With VR on, you may choose either NORMAL or SPORT mode. In SPORTS mode, Nikon VR recognizes a panning motion and compensates for camera shake while preserving intended motion blue due to panning.
  • Lock 200: This switch locks the lens at a 200mm focal length during transportation and storage. With the lock disengaged, the lens may be zoomed to any point in the focal length range.
This photo shows the Nikon F-mount flange on the 200-500 f/5.6E lens. Notice the rubber gasket which provides a seal between the lens and camera body for protection from weather and the elements. The lens also features a rubberized ring at the front of the lens, also for weather sealing. (Bill Ferris)

This photo shows the Nikon F-mount flange on the 200-500 f/5.6E lens. Notice the rubber gasket which provides a seal between the lens and camera body for protection from weather and the elements. (Bill Ferris)

The rubberized seal around the front of the Nikon 200-500mm f/5.6E ED VR provides both protection for the front lens element and a measure of weather sealing from the elements. (Bill Ferris)

The rubberized seal around the front of the Nikon 200-500mm f/5.6E ED VR provides both protection for the front lens element and a measure of weather sealing from the elements. (Bill Ferris)

After shooting with this lens for a bit longer than one month, I would describe the construction and controls as of good to very good quality. The collapsed lens feels hefty and solid in the hands. There is plenty of plastic in the external shell but the lens does not feel, cheap. There are no odd internal sounds when shaking the lens, and not clicking or grinding sounds when rotating either zoom or focus. The tripod collar is sturdy with the mounting foot serving perfectly as a handle when carrying just the lens.

The zoom ring, located near the end of the lens, is rubberized and has smooth motion with just the right degree of tension. I would describe the sound made by the rotating zoom ring as smooth zippy. The throw (angle of rotation through the complete zoom range) is fairly long at approximately 155 degrees and this makes it difficult to quickly zoom from one end of the range to the opposite. The focus ring, located near the back of the lens just in front of the control cluster has a hard plastic feel and loose rotation action. It makes a whispery sound when rotated and has a throw of about 190 degrees. I typically shoot with the lens focus control set to M/A (Auto with instantaneous manual override) and have not had any instances where I unintentionally brushed against or rotated the focus ring to lose focus.

The lens hood and soft case that ship with the Nikon 200-500mm f/5.6E are cheap, low quality items. The lens hood is functional, at best, while the soft case is of marginal value unless repurposed to something other than its intended task. (Bill Ferris)

The lens hood and soft case that ship with the Nikon 200-500mm f/5.6E are cheap, low quality items. The lens hood is functional, at best, while the soft case is of marginal value unless repurposed to something other than its intended use. (Bill Ferris)

The 200-500mm f/5.6E ships with a lens hood and soft case. These are, quite frankly, fairly cheap low quality items. The lens hood locks in place with a quarter turn. It is not a firm, confident lock. Rather, the hood issues a soft click when locked in position and can be easily rotated to unlock. There have been a couple of occasions when I’ve inadvertently bumped the lens hood enough to either rotate it or flex it just enough to loosen the connection. The soft case is just that. The only padding is a thin sheet at the bottom of the case.

Just a couple of weeks after the lens started shipping, Nikon Europe announced a firmware upgrade to address and correct a bug in the lens’ autofocus performance. In summary, when simultaneously engaging autofocus while zooming, autofocus will occasionally shift to manual mode. Autofocus can be restored by releasing the shutter, AF-ON or AE-L/AF-L button and then re-engaging so, this is not a catastrophic issue. I would describe it as an annoyance. In online discussion forums, some photographers have questioned the value of the firmware upgrade saying they never simultaneously zoom while engaging autofocus.

Others, myself among them, say the technique is one they employ on a more or less regular basis. When photographing sports or wildlife, I will often adjust zoom and focus, simultaneously, in order to maintain both good composition and focus while tracking a fast-moving subject. Rather than wait for Nikon to send me a personalized invitation, I visited the Nikon USA website and found their statement about the firmware upgrade. Nikon treats this, not as a service under warranty issue, but rather as an optional upgrade which is available to their US customers. Nikon paid for expedited 2nd day shipping to and from their Los Angeles facility. The lens was in their possession for two business days and Nikon kept me informed via email of the status of the work being done.

UPS delivered the upgraded lens on October 15. The following morning, I tested the autofocus performance by using back button focus to keep AF engaged while simultaneously panning and zooming between two trees in my backyard. Autofocus continued to work while I panned and zoomed from one tree to another more distant tree, repeating this motion twenty times.

The autofocus bug continues a trend for Nikon of shipping new products with performance issues. It is a problem that dates back at least to 2012, including the D800/D800E camera bodies (2012-left side autofocus), D600 body (2012- dust and oil on sensor), D750 body (2014-dark banding when shooting backlit subjects), D810 body (2014-bright spots in image during long exposures), 24-70mm f/2.8E ED VR zoom lens (2015-shipping date delayed) and now the 200-500mm f/5.6E. It is an annoying and disturbing development for a company that used to be known for producing and delivering high quality products. Nikon has now developed a reputation of poor quality control during product development and of using early adopting customers as beta testers. If there is a silver lining in this, it is that Nikon has been more proactive and acknowledging and responding to problems with new products over the last year or so.

With the tripod collar locking mechanism loosened, rotate the collar until the indicator with the carrot is aligned with both the F-mount indicator dot and the collar alignment indicator on the lens. In this orientation, the collar should slide easily off the back of the lens. (Bill Ferris)

With the tripod collar locking mechanism loosened, rotate the collar until the indicator with the carrot is aligned with both the F-mount indicator dot and the collar alignment indicator on the lens. In this orientation, the collar should slide easily off the back of the lens. (Bill Ferris)

If you are unfamiliar with Nikon tripod collars, figuring out how to remove the collar from the tripod can be a bit confusing. The collar is not hinged and does not open fully for removal. Rather, when the locking mechanism is loosened, the collar open just enough to slide over the back of the lens. However, the collar features an interior channel which slides over four locking screws on the lens. To align the locking screws with openings in the collar channel, rotate the loosened collar until the indicator with the carrot is aligned both with the F-mount indicator dot and with the collar alignment indicator on the camera. With the collar rotated as shown in the above photo, it should slide easily off the back of the lens.

Well, now that the housekeeping is taken care of, let’s focus on the central question: is the AF-S 200-500mm f/5.6E ED VR lens a quality optic? Does it, for want of a better metaphor, punch above its weight class to deliver performance exceeding what one typically gets when shooting with a sub-$1,500 telephoto zoom? Let’s look at some sample photos. Full-sized JPEG’s of the below images are available for viewing by right-clicking on the image.

A coot shakes off pond water at Raymond County Park in Kachina Village, Arizona. This photo was taken with the Nikon D610 and 200-500mm f/5.6E at 500mm, f/5.6, ISO 1400, 1/100-second. It has been cropped and processed in Adobe Lightroom to taste. (Bill Ferris)

A coot shakes off pond water at Raymond County Park in Kachina Village, Arizona. This photo was taken with the Nikon D610 and 200-500mm f/5.6E at 500mm, f/5.6, ISO 1400, 1/100-second. It has been cropped and processed in Adobe Lightroom to taste. (Bill Ferris)

A Eurasian Eagle Owl stands stoically on its perch during a raptors show at Flagstaff Arboretum. This photo was taken with the Nikon D610 and 200-500mm f/5.6E at 500mm, f/5.6, ISO 4000, 1/500-second. It has been processed to taste in Adobe Lightroom. (Bill Ferris)

A Eurasian Eagle Owl stands stoically on its perch during a raptors show at Flagstaff Arboretum. This photo was taken with the Nikon D610 and 200-500mm f/5.6E at 500mm, f/5.6, ISO 4000, 1/500-second. It has been processed to taste in Adobe Lightroom. (Bill Ferris)

A waning gibbous Moon hangs silently over Flagstaff on a mid-autumn night. This photo was taken with the Nikon D610 and 200-500mm f/5.6E at 500mm, f/5.6, ISO 400, 1/1250-second. It has been cropped processed to taste in Adobe Lightroom. (Bill Ferris)

A waning gibbous Moon hangs silently over Flagstaff on a mid-autumn night. This photo was taken with a Nikon D610 and 200-500mm f/5.6E at 500mm, f/5.6, ISO 400, 1/1250-second. It has been cropped processed to taste in Adobe Lightroom. (Bill Ferris)

A Weber State running back sprints to the right during a game against Northern Arizona in the J. L. Walkup Skydome. This photo was taken with the Nikon D610 and 200-500mm f/5.6E at 400mm, f/5.6, ISO 6400, 1/200-second. It has been cropped processed to taste in Adobe Lightroom. (Bill Ferris)

A Weber State running back sprints to the right during a game against Northern Arizona in the J. L. Walkup Skydome. This photo was taken with a Nikon D610 and 200-500mm f/5.6E at 400mm, f/5.6, ISO 6400, 1/200-second. It has been cropped processed to taste in Adobe Lightroom. (Bill Ferris)

A dark-eyed junco sits perched on a tree branch in Raymond County Park in Kachina Village, Arziona. This photo was taken with the Nikon D610 and 200-500mm f/5.6E at 500mm, f/5.6, ISO 2800, 1/1000-second. It has been cropped processed to taste in Adobe Lightroom. (Bill Ferris)

A dark-eyed junco sits perched on a tree branch in Raymond County Park in Kachina Village, Arziona. This photo was taken with the Nikon D610 and 200-500mm f/5.6E at 500mm, f/5.6, ISO 2800, 1/1000-second. It has been cropped processed to taste in Adobe Lightroom. (Bill Ferris)

A monarch butterfly rests momentarily atop a New Mexico thistle flower at Logan's Crossing near Flagstaff, Arizona. This photo was made with a Nikon D610 and 200-500mm f/5.6E at 500mm, f/5.6, ISO 400, 1/1000-second. It has been cropped and processed to taste in Adobe Lightroom. (Bill Ferris)

A monarch butterfly rests momentarily atop a New Mexico thistle flower at Logan’s Crossing near Flagstaff, Arizona. This photo was made with a Nikon D610 and 200-500mm f/5.6E at 500mm, f/5.6, ISO 400, 1/1000-second. It has been cropped and processed to taste in Adobe Lightroom. (Bill Ferris)

Cheerleaders celebrate a Northern Arizona touchdown during a college football game at the J. L. Walkup Skydome in Flagstaff, Arizona. This photo was made with a Nikon D610 and 200-500mm f/5.6E at 500mm, f/5.6, ISO 8063, 1/500-second. It has been cropped and processed to taste in Adobe Lightroom. (Bill Ferris)

Cheerleaders celebrate a Northern Arizona touchdown during a college football game at the J. L. Walkup Skydome in Flagstaff, Arizona. This photo was made with a Nikon D610 and 200-500mm f/5.6E at 500mm, f/5.6, ISO 8063, 1/500-second. It has been cropped and processed to taste in Adobe Lightroom. (Bill Ferris)

American Coots casually scan for snacks in a Kachina Village pond. This photo was made with a Nikon D610 and 200-500mm f/5.6E at 500mm, f/5.6, ISO 3600, 1/1000-second. It has been cropped and processed to taste in Adobe Lightroom. (Bill Ferris)

American Coots casually scan for snacks in a Kachina Village pond. This photo was made with a Nikon D610 and 200-500mm f/5.6E at 500mm, f/5.6, ISO 3600, 1/1000-second. It has been cropped and processed to taste in Adobe Lightroom. (Bill Ferris)

Weber State quarterback, Jadrian Clark, stretches toward the goal line late in the 3rd quarter of a game against Northern Arizona in the J. L. Walkup Skydome. This photo was taken with a Nikon D610 and 200-500mm f/5.6E at 480mm, f/6.3, ISO 8063, 1/500-second. It has been cropped and processed to taste in Adobe Lightroom. (Bill Ferris)

Weber State quarterback, Jadrian Clark, stretches toward the goal line late in the 3rd quarter of a game against Northern Arizona in the J. L. Walkup Skydome. This photo was taken with a Nikon D610 and 200-500mm f/5.6E at 480mm, f/6.3, ISO 8063, 1/500-second. It has been cropped and processed to taste in Adobe Lightroom. (Bill Ferris)

A third quarter Moon as seen on an October night in northern Arizona. This photo was taken with a Nikon D610 and 200-500mm f/5.6E at 500mm, f/5.6, ISO 900, 1/800-second. It has been cropped and processed to taste in Adobe Lightroom. (Bill Ferris)

A third quarter Moon as seen on an October night in northern Arizona. This photo was taken with a Nikon D610 and 200-500mm f/5.6E at 500mm, f/5.6, ISO 900, 1/800-second. It has been cropped and processed to taste in Adobe Lightroom. (Bill Ferris)

A dark-eyed junco in Raymond County Park in Kachina Village, Arizona. This photo was taken with a Nikon D610 and 200-500mm f/5.6E at 500mm, f/5.6, ISO 3600, 1/1000-second. It has been cropped and processed to taste in Adobe Lightroom. (Bill Ferris)

A dark-eyed junco in Raymond County Park in Kachina Village, Arizona. This photo was taken with a Nikon D610 and 200-500mm f/5.6E at 500mm, f/5.6, ISO 3600, 1/1000-second. It has been cropped and processed to taste in Adobe Lightroom. (Bill Ferris)

An Abert squirrel gnoshes on pine nuts in a northern Arizona Ponderosa pine tree. This photo was made with a Nikon D610 and 200-500mm f/5.6 at 480mm, f/5.6, ISO 1400, 1/125-second. It has been cropped and processed to taste in Adobe Lightroom. (Bill Ferris)

An Abert squirrel gnoshes on pine nuts in a northern Arizona Ponderosa pine tree. This photo was made with a Nikon D610 and 200-500mm f/5.6 at 480mm, f/5.6, ISO 1400, 1/125-second. It has been cropped and processed to taste in Adobe Lightroom. (Bill Ferris)

A peregrine falcon sits calmly on the arm of a volunteer during a raptor show at the Arboretum at Flagstaff. This photo was made with a Nikon D610 and 200-500mm f/5.6E at 500mm, f/5.6, ISO 3200, 1/500-second. It has been processed to taste in Adobe Lightroom. (Bill Ferris)

A peregrine falcon sits calmly on the arm of a volunteer during a raptor show at the Arboretum at Flagstaff. This photo was made with a Nikon D610 and 200-500mm f/5.6E at 500mm, f/5.6, ISO 3200, 1/500-second. It has been processed to taste in Adobe Lightroom. (Bill Ferris)

A Eurasian Eagle Owl watches visitors from its perch during a raptors show at the Arboretum at Flagstaff. This photo was taken with a Nikon D610 and 200-500mm f/5.6E at 500mm, f/5.6, ISO 2800, 1/500-second. It has been processed to taste in Adobe Lightroom. (Bill Ferris)

A Eurasian Eagle Owl watches visitors from its perch during a raptors show at the Arboretum at Flagstaff. This photo was taken with a Nikon D610 and 200-500mm f/5.6E at 500mm, f/5.6, ISO 2800, 1/500-second. It has been processed to taste in Adobe Lightroom. (Bill Ferris)

After my first month shooting with the AF-S 200-500mm f/5.6E ED VR telephoto zoom, I find the lens to be very sharp, delivering crisp detailed images of nature and wildlife.  If you open the above image of the Eurasian eagle owl (the last in the sequence) in a new tab and zoom in, you’ll see my silhouetted form clearly defined in the owl’s pupil. You’ll see similar results in the full-size JPEG images of the peregrine falcon and in the first photograph of the Eurasian eagle owl.

The detail in the lunar photos is very sharp. At 500mm, the lens easily resolves craters of approximately 10 kilometers diameter and partially resolves 1 kilometer wide craters on the Moon’s surface. Details such as bright ejecta rays and dark maria are also easily discerned. Chromatic aberration along the lunar limb is negligible and quite easily eliminated with the click of a button in Lightroom.

Check out the detail in the Abert’s squirrel photo. I shot this from a forest path with the squirrel about 30 feet up in a tree. Focus is on the squirrel’s hind leg but, at f/5.6, there is enough depth of field that the eye is acceptably sharp. The best detail in this image is in that hind leg, in the toes, claws and padding on the bottom of the foot. And check out the small bit of green – a freshly sprouted branch – on the bark below the squirrel’s bushy tail.

The photos of the dark-eyed junco show good focus on the eye, fine detail in the feathers and a very pleasing creamy bokeh. This lens handles background blur in a wonderful manner. The bokeh is smooth and soft, and more than adequate to create the desired separation between the subject and background. The junco photos were made from a distance of about 50 feet. The photos of the American coots were made at various distances, ranging from about 20 feet to a greatest distance of nearly 80 feet. The eyes and water droplets are crisp and well-defined. The feathers show good detail and texture. When you consider this high level of performance is made available in a lens priced thousands less than the Nikon telephotos that most closely compete with it in terms of sharpness, contrast and general image quality, the 200-500mm f/5.6E is truly an astounding value.

If you can’t make outstanding images with this lens, it’s not the lens’ fault.

With 12-seconds left in regulation, NAU's Dan Galindo hauls in a Jordan Perry pass to score the game-winning touchdown

With 12-seconds left in regulation, NAU’s Dan Galindo hauls in a Jordan Perry pass to score the game-winning touchdown. This photo was made with a Nikon D610 and Tamron 70-200 f/2.8 Di VC USD lens at 70mm, f/2.8, ISO 8063, 1/1000-second. It has been cropped and processed to taste in Adobe Lightroom. (Bill Ferris)

The photos from the football game illustrate the most significant limitations of the lens. Those are its limited – in comparison with high end professional telephoto primes and zooms – light gathering ability and less-than-nimble autofocus performance. Let’s talk first about the light-gathering ability of the 200-500mm f/5.6E lens.

The game was played in the J. L. Walkup Skydome on the campus of Northern Arizona University. This is not a well-lit venue. The above photo of a game-winning touchdown reception was taken during a 2014 game in the Skydome. Shooting with a Tamron 70-200mm f/2.8 Di VC USD lens at 70mm f/2.8, my Nikon D610 camera body used ISO 8063 (Hi 0.3) to make a properly exposed image at 1/1000-second. This should give you an idea of the generally dim light level  (for photography) in this venue.

The 200-500mm f/5.6E delivers a constant f/5.6 focal ratio, which is two full stops slower than an f/2.8 lens. To manage the ISO and retain a minimal degree of noise-free clarity, I chose to use exposures ranging from 1/200-second to 1/500-second. Shooting at 1/200 to 1/500-second won’t come close to freezing the action of a college football game. The ISO’s chosen by the D610 at these exposure lengths generally ranged from ISO 6400 to ISO 8063 (Hi 0.3).

Starting about midway into the 3rd quarter, I shot with the 200-500 from the north end zone and photographed the action until midway through the 4th quarter. I would describe the autofocus performance as good but not impressive. This is not a lightning fast focusing lens.

I also need to acknowledge that my long telephoto lens skills are still in development. Prior to getting the 200-500, my longest lens had been the Nikon AF-S 70-300 f/4.5-5.6 ED VR. This is a consumer quality telephoto zoom. It is not impressively sharp but does offer good reach at a reasonable price. It’s also nicely portable and lightweight. In July 2015, I used the 70-300 to photograph a battle between two bison bulls for herd dominance on the North Rim of Grand Canyon. It was an exhilarating moment and the lens performed, well. However, it was that experience that got me seriously thinking about adding a long telephoto zoom to my kit. The 300mm maximum reach just wasn’t enough for that moment.

The Nikon AF-S 200-500mm f/5.6E ED VR lens mounted to an Oben CTM-2500 monopod and VH-R2 monopod tilt head. (Bill Ferris)

The Nikon AF-S 200-500mm f/5.6E ED VR lens mounted to an Oben CTM-2500 monopod and VH-R2 monopod tilt head. (Bill Ferris)

Anticipating the size, weight and magnification of the 200-500 would exceed my capacity for handholdable comfort, I purchased an Oben model CTM-2500 carbon fiber monopod to support the lens. Pictured above, is the Nikon lens mounted to the Oben monopod and VH-R2 monopod tilt head. I’ve used this combination extensively during this first month of ownership and I have to admit the monopod was a great investment. It’s carbon fiber construction makes the monopod very light, weighing in at just 1 lb. 10 oz with the attached VH-R2 head. It is a five-section design which collapses to a respectable and compact 19 3/4″ length including the tilt head. Every photo in this article taken with the 200-500 was made with the lens mounted to the Oben monopod.

There is one major criticism I have of the Oben CTM-2500 monopod. I don’t like the mounting plate that comes with the VH-R2 tilt head. It is not a standard size plate. As a result, I can’t attach a Peak Design mounting plate to the 200-500’s tripod collar foot. Also, the Oben mounting plate has a spring-loaded second pin that doesn’t have a matching companion hole in most tripod collar feet. The bottom of the 200-500’s tripod collar foot is lined with channels that provide some degree of purchase for the Oben pin. However, after a few days, the Oben plate inevitably becomes loose enough that I have to tighten the primary 1/4×20 threaded bolt to establish a secure connection.

One significant area of personal development over the first month of ownership of this lens has very little to do with photography. It is simply the challenge of becoming comfortable handling a lens of this size and weight. It’s only been in the last week or so that I’ve started feeling at ease carrying and handling the lens. It is much larger and heavier than any other lens I’ve owned or used. During the first few weeks of ownership, I was constantly worried about banging it against a wall, into a door frame or even hitting a person.

I’m also developing the ability to get close to wildlife. The challenge is to get as close to your subject as possible without encroaching such that your presence causes unnatural behaviors in the animal. Getting close is as much an art form as a skill. It requires a knowledge and skill set that has nothing, per se, to do with photography. It has everything to do with being invisible and/or perceived as a non-threat to the animal.

Once in position, achieving good results comes down to your skill in employing basic and advanced techniques of doing photography at super telephoto ranges. While the 500mm reach of the new lens has allowed me to achieve images I could previously only have imagined, I am not yet fully comfortable working at such a long focal length. This lens challenges my ability to anticipate and follow action, maintain good composition and employ good focusing technique. The margin of error in these areas is much wider when using shorter focal lengths. When working at 300mm, 400mm or more, precision in composition, tracking and technique is essential. While my skill and comfort working with this zoom range is improving, I am not yet where I want to be.

Weber State prepares to snap the ball from the 2-yard line, late in a game against host Northern Arizona. (Bill Ferris)

Weber State prepares to snap the ball from the 1-yard line, late in a game against host Northern Arizona. This photo was made with a D610 and the 200-500mm f/5.6E at 500mm, f/6.3, ISO 8063, 1/500-second. (Bill Ferris)

One photographic skill that is critical to successful photography at super telephoto lengths, is autofocus technique. I have experimented with a variety of modes available on the D610 body. I always use AF-C mode when photographing moving subjects and have been hopping about between single-point, 9-point and 3D modes. Depending on the situation, each offers its own advantages. I’m also experimenting with AF settings defining the length of time the lens will hold focus before resetting.

This brings me to a comment about the most-cited weakness of Nikon’s newest super telephoto zoom; its “poor” autofocus performance. This is, according to experts in online fora, the biggest weakness of the lens. Many of the self-appointed experts haven’t shot with the 200-500 and are relying on the comments of their favorite expert photographer…typically, a photographer who expresses a view they’ve predetermined to be correct. As mentioned previously in this review, the 200-500 does not have lightning fast autofocus. Nonetheless for many photographers, the biggest limitation impeding the quality of results achieved with this lens will be their own lack of experience working at such long focal lengths. Before blaming the lens, be sure it isn’t your own poor technique that costs you the cover of National Geographic.

Since I’ve only been using the lens a month and am still learning to master the challenges that come with shooting at super telephoto range, I’m going to suspend my final judgement on the AF performance of the 200-500 until I’ve eliminated user error as a significant contributing factor. I know for a fact that my own poor technique has cost me potentially good shots. When those instances have been eliminated – or at least, nearly so – I’ll be in a better position to comment with some degree of expertise on the inherent AF performance of this lens.

An American coot dips its beak into the Raymond County Park pond in search of a snack. This photo was made with a Nikon D610 and 200-500mm f/5.6E at 500mm, f/5.6, ISO 1400, 1/1000-second. It has been cropped and processed to taste in Adobe Lightroom. (Bill Ferris)

An American coot dips its beak into the Raymond County Park pond in search of a snack. This photo was made with a Nikon D610 and 200-500mm f/5.6E at 500mm, f/5.6, ISO 1400, 1/1000-second. It has been cropped and processed to taste in Adobe Lightroom. (Bill Ferris)

And with that, I’ll bring this Short Term Review to a close. These are my thoughts on the Nikon AF-S 200-500mm f/5.6 E ED VR lens after one-month’s ownership and use. As my time and experience with this lens increases, I will return to this blog with additional observation and thoughts on this super telephoto zoom. For now, I would sum up my observations and impressions, as follows:

The 200-500mm f/5.6E is fantastically sharp, wide open at 500mm and delivers outstanding VR performance. Priced at just under $1,400 US, this lens does not have the equivalent build quality or autofocus performance of the top professional Nikon telephoto primes and zooms. That said, this lens is an incredible value and can be a tool helping to elevate your wildlife, nature and outdoor sports photography to new levels.

Now, get out and shoot!

Bill Ferris | November 2015

What the f/#?

The Tamron 70-200 f/2.8 Di VC USD zoom lens has a focal ratio of f/2.8. This defines the largest aperture the lens is capable of having at all focal lengths throughout the zoom range. Operating at f/2.8, the focal length selected will be 2.8X the size of the aperture. While the focal length range is 70-200mm, the range of largest apertures is 25mm at a 70mm focal length to 71mm at 200mm focal length.

The Tamron 70-200 f/2.8 Di VC USD zoom lens has a constant focal ratio of f/2.8. This defines the largest aperture the lens will have throughout the zoom range. Operating at f/2.8, the focal length selected will be 2.8X the aperture. With a focal length range of 70-200mm, the widest aperture varies from 25mm at a focal length of 70mm to 71mm at a 200mm focal length. (Bill Ferris)

Let’s nerd out with some tech talk. Let’s chat about focal ratio.

Focal ratio is a rarely seen or heard phrase in online photography blogs and forums, which is surprising when you consider the important role focal ratio plays in photography. Focal ratio describes the size of a lens’s focal length relative to its aperture. It is typically expressed as an f-number, such as f/2.8. Ironically, when photographers start talking about lens aperture, it’s more than likely they’re actually discussing focal ratio. Let’s see if we can sort all this out.

We’ll begin at the beginning. Focal length is typically the first number mentioned when describing a lens. A 50mm lens has a focal length of, wait for it…50mm or roughly two inches. One may be inclined to think focal length is the distance from the front of the lens to the back, but it’s not. Focal length is the distance from the optical center of the lens to the image plane (film or sensor) where the image is formed. The optical center is usually inside the lens and is sometimes referred to as the point of convergence; the point where two light rays converge and cross.

The above diagram shows a cross section of the Nikkor 50mm f/1.4 lens. The focal length of the lens is 50mm, which is measured from the optical center of the lens to the image plane at the sensor.

The above diagram shows a cross section of the Nikkor 50mm f/1.4 lens. The focal length of the lens is 50mm, which is measured from the optical center of the lens to the image plane at the sensor.

Focal length determines how much the image is magnified. This is typically described as the angle of view produced by the lens. A 50mm lens produces a 47° (on a diagonal) angle of view at the image plane of a 35mm camera body. A 24mm lens delivers an 84° angle of view and a 200mm lens presents a 12° angle of view. Since the angle of view produced by a 50mm lens is similar to that of normal vision, it is known in 35mm photography as a normal lens. 24mm is a wide angle focal length and a 200mm is a telephoto lens.

Of course, 35mm is just one of many photographic formats. A photographic format is defined by the physical size of the medium used to record the image. In film photography, 35mm describes the length of the long side of a slide or film negative. Today’s digital cameras use light-sensitive CMOS sensors to record images. In full frame digital cameras, the sensor measures 36mm on the longest side. APS-C digital cameras have sensors that are about 23mm on the longest side. The camera in your smartphone or tablet is probably built around a sensor no larger than about 10 millimeters. What does sensor size have to do with this topic? A lot.

The above diagram illustrates the relative sizes of common digital camera sensor formats. The largest shown is a full frame (FX) sensor. The smallesst (lower left corner) is representaive of a typical smart phone (1/2.3") sensor.

The above diagram illustrates the relative sizes of common digital camera sensor formats. The largest shown is a full frame (35mm equivalent) sensor. The smallest (lower left corner) is representative of a smartphone (1/2.3″) sensor.

The smaller the sensor or film medium, the farther you need to be from your subject to match the field of view delivered by a given focal length lens. Imagine standing 10 feet from your subject with a full-frame DSLR camera and framing your subject head-to-toe using a normal 50mm lens. If you were to mount the same lens on an APS-C camera body, that camera’s smaller sensor would cut off or crop a portion of the image produced by the lens. You would need to step back to a distance of about 15 feet to reproduce the angle of view you had with the full frame camera body.

Another factor to consider when shooting with a “crop sensor” body is the effect of sensor size on depth of field. Depth of field (DOF) is the range of distances – nearest to farthest – in an image that appear acceptably sharp and in-focus. DOF is determined by magnification (lens focal length) and by the lens focal ratio or f-number. In a nutshell, bringing the subject closer decreases depth of field. Moving the subject farther away increases depth of field. As depth of field increases, a deeper portion of the image appears in focus. As depth of field decreases, only a narrow or shallow range looks sharp and in focus.

Both photographs were made using a Nikon D610 with Tamron 70-200 Di VC USD zoom lens at 125mm. The image on the left was shot at f/2.8 and has a much shallower depth of field. The image on the right was shot at f/32 and presents a much wider depth of field.

The above photographs were made using a Nikon D610 and Tamron 70-200mm f/2.8 Di VC USD zoom lens at 125mm. The image on the left was shot at f/2.8 and has a much shallower depth of field. The image on the right was shot at f/32 and shows much more of the field in focus.

As mentioned, focal ratio also has an effect on depth of field. For any given focal length, increasing focal ratio (making the f-number larger) increases depth of field while decreasing focal ratio (making the f-number smaller) reduces depth of field. We’ve already discussed the cropping effect of shooting with a smaller sensor. Stepping back to reproduce a desired angle of view increases depth of field. Zooming or changing lenses to shoot with a shorter focal length (to match the field of view provided by a full frame sensor body) increases depth of field.

One can compensate for the increased depth of field which results from the adjustments commonly made to expand the angle of view delivered by a crop sensor camera by shooting with smaller f-numbers. For example, shooting with a 35mm lens at f/1.4 will allow an APS-C sensor body to produce photographs having the same framing and depth of field as images made from the same position using a 50mm f/2.0 lens on a full frame body.

Let’s explore this in a bit more detail. Suppose you’re shooting with two cameras, one full frame and the other a crop sensor, and using the same 50mm lens with both. Its effective focal length (the focal length matching the angle of view delivered to the sensor) will be 50% longer or 75mm on the APS-C body. At f/4, the 50mm lens will have an aperture of 12.5mm. If we step back to compensate for the more narrow angle of view, the effective focal ratio (the focal ratio delivering an equivalent depth of field from the distance at which this lens matches the angle of view delivered to a full frame camera) will be f/6. Its effective 75mm focal length divided by the 12.5mm aperture equals six.

Do you see the relationship? We’re using an f/4 lens on an APS-C body. When the goal is to match the angle of view and depth of field produced by a full frame camera, we can determine the effective focal ratio at which a crop sensor camera needs to operate by dividing the focal ratio of the lens by the crop factor. The crop factor is 1.5 and the effective focal ratio (for depth of field) is f/6.

Here’s an illustration.

These images illustrate how to use a crop sensor camera to match both the angle of view and the depth of field delivered by a full frame body. I used a Nikon D610 and Nikon D90 to make photographs of the same toy caboose. Both cameras used a Tamron 70-200 f/2.8 Di VC USD lens. The lens was mounted on a tripod and the bodies switched out to ensure the lens would not move from its position during the test. The D610 uses a 36mm sensor and shot at 105mm, f/4 to make both images. The D90 uses an APS-C sensor with a 1.5X crop factor. I shot at 75mm, f/4 to make the first image. Comparing the first (top) images, we see that the D90 delivered a similar angle of view as the D610 but a comparison of the background shows the D610 to have a more shallow depth of field. The background in the D90 image is just skosh nearer to being in focus. For the second image, I applied the conversion factor and shot with the D90 at 70mm, f/2.8. A comparison of this image with the D610 image shows both to have delivered similar angles of view and similar depth of field. (Bill Ferris)

These images illustrate how to use a crop sensor camera to match both the angle of view and the depth of field delivered by a full frame body. I used a Nikon D610 and Nikon D90 to make photographs of the same toy caboose. Both cameras used the same Tamron 70-200 f/2.8 Di VC USD lens. The lens was mounted on a tripod and the bodies switched out to ensure the lens would not move from its position during the test. The D610 is built around a 36mm sensor and was used at 105mm, f/4 to make both images. The D90 has an APS-C sensor with a 1.5X crop factor. I shot at 70mm, f/4 to make the first image. Comparing the first (top) images, we see that the D90 delivered a similar angle of view as the D610 but a comparison of background detail reveals the D610 to have a more shallow depth of field. The background in the D90 image is just a skosh nearer to being in focus. For the second image, I applied the conversion factor and shot with the D90 at 70mm, f/2.8. A comparison of this image with the D610 image shows both to have delivered similar angles of view and similar depth of field. (Bill Ferris)

So, we’ve demonstrated that, in comparison with full frame cameras, crop sensor camera bodies produce images having narrower angles of view and, when adjustments are made to compensate for this, increased depth of field. We’ve also demonstrated that you can compensate for these performance factors. Either increase the distance between you and the subject or use a shorter focal length to increase the angle of view. Shoot at a smaller focal ratio (f-number) to make the depth of field more shallow. Next, we’ll explore the relationship between sensor size and length of exposure. Here’s a heads up, the outcome may not be what you expect.

I used my Nikon D610 (full frame) and Nikon D90 (APS-C) to take a series of exposures of a toy train engine. The toy steam engine was set up outside on a small tray table. The sky was overcast with nice, even lighting throughout the test. Both bodies used the same Tamron 70-200mm f/2.8 Di VC USD lens, which was set at 70mm. I selected ISO 200 on both cameras for all exposures. The zoom lens was set up on a tripod and the camera bodies were switched out without changing the position of the lens. I used each camera to make exposures at f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22 and f/32. I shot in aperture priority on both cameras and let their internal brains select the proper exposure.

Below, are pairs of images showing the photographs made at the same settings with the two bodies, side-by-side. All are unedited JPEGs. Keep in mind that the sensor in the D90 body cropped the image to match the angle of view produced by a 105mm lens.

In this comparison, photographs of the same subject made with a Nikon D610 (left) and a Nikon D90 (right) are shown, side-by-side. Both cameras shot at ISO 200. Both cameras used the same Tamron lens at 70mm. The lens was mounted on a tripod to ensure it would remain in the same position throughout the test. For each focal ratio, both cameras used the same exposure. (Bill Ferris)

In this comparison, photographs of the same subject made with Nikon D610 (left) and Nikon D90 (right) cameras are shown, side-by-side. Both cameras were set to ISO 200. Both cameras used the same Tamron lens at 70mm. The lens was mounted on a tripod to ensure it would remain in the same position throughout the test. At each focal ratio, both cameras metered the scene as having the same brightness and chose the same exposure. (Bill Ferris)

Let’s talk more about this f-number thing. You’ll recall that focal ratio describes the ratio of the focal length of the lens to the aperture of the lens. A 50mm lens at f/2.0 has a focal length that is 2-times its aperture. Therefore, the lens aperture at f/2.0 will be 25mm. At f/4.0, the aperture is 12.5mm; at f/8.0, 6.25mm and so on. The relationship between aperture and focal ratio is pretty straight forward: for any given focal length, decreasing aperture increases focal ratio and increasing aperture decreases focal ratio.

Rarely, however, do photographers talk about the f-number as a focal ratio. More commonly, they talk about it as a lens aperture. They talk about an f/2.0 lens having a larger aperture than an f/4.0 lens. It’s an accurate statement, if we’re talking about the same lens at different focal ratios. But this is just one of many scenarios where focal ratios are compared.

Let’s consider the scenario of discussing different lenses. Suppose we’re comparing a 50mm lens to a 100mm lens. Suppose the 50mm lens is being used at f/2 and the 100mm lens is set to f/4. One might think the 50mm lens, by virtue of having a smaller f-number, will have a larger aperture. In fact, both lenses have identical 25mm apertures. It simply isn’t the case that every f/1.4 lens has a larger aperture than every f/8 lens. In reality, it is quite common for a lens operating at a large f-number to have a larger aperture than a lens working at a small f-number. I would wager to guess that there isn’t a focal ratio at which a 600mm lens doesn’t have a larger aperture than the fastest focal ratio smartphone.

One quality that does translate across different lenses and cameras, is the speed of the imaging system. What does speed have to do with photography? To understand, it helps to think of a properly exposed photograph as one where a certain intensity of light needs to fall upon the sensor at the image plane. Think of light as water, the sensor as a container used to collect water (light) and the lens as the opening through which water is poured into the container.

That said – and this next point is critical – a properly exposed image is not determined by the total quantity of light delivered to the sensor. The length of a proper exposure is determined by the average brightness of the image falling on the sensor. To better understand this, we’re going to introduce a new concept: surface brightness.

The above illustrates the concept of Surface Brightness in photography. For a properly exposed image, the camera's optical system must collect and deliver light having a surface brightness (brightness or intensity per square millimeter) to the sensor. This is represented by the evenly deep layer of "blue" light collected bu the sensor. If you use the same lens on a crop sensor body, the same intensity of light (represented by the central red region) is delivered to the sensor. Being smaller, the crop sensor collects less total light. However, the surface brightness of the image (the brightness per square millimeter) is identical to that of the larger sensor. (Bill Ferris)

The above illustrates the concept of Surface Brightness in photography. For a properly exposed image, the camera’s optical system must collect and deliver light having a surface brightness (brightness per square millimeter) to the sensor. This is represented by the thick layer of “blue” light collected by the sensor. The thickness of the layer represents the intensity or average brightness of the image. If we use the same lens on a crop sensor body, the same intensity (thickness) of light is delivered to the sensor. This is represented by the central red zone on the sensor. Being smaller, the crop sensor collects less total light. However, the surface brightness of the image is identical to that of the larger sensor. (Bill Ferris)

Earlier, a correct exposure was described as one where a container (sensor) is filled to the correct depth (intensity) with water (light). It doesn’t matter if the container is large enough to hold one gallon or 100 gallons. As long as it’s filled to the proper depth, the exposure will be good. In this example, the depth of the water represents the average brightness of the image at the image plane. Another way to describe the average brightness or intensity of light, is to talk about image surface brightness.

Surface brightness is defined as a brightness per unit area. In photography, we can define surface brightness as the brightness of light per square millimeter falling on the film or sensor. It is not a total volume or quantity of light. Rather, it is an average intensity of light. Surface brightness is strictly determined by the focal ratio of the optical system. The lens f-number determines the length of the exposure needed to deliver light of a certain intensity to the sensor. A full frame camera, crop sensor camera and smartphone camera focused on the same subject – and all operating at f/2.0 – will deliver the same light intensity per square millimeter (the same surface brightness) to their respective sensors during the same length exposure.

The relative sizes of full frame (pink) and APS-C (blue) sensors is illustrated above. The effects of a crop frame sensor include an increase in effective focal length and an increase in effective depth of field.

The relative sizes of full frame (pink) and APS-C (blue) sensors is illustrated above. The effects of a crop frame sensor include an increase in effective focal length and effective depth of field.

Despite the fact that a crop sensor doesn’t collect as much total light during an exposure as a full frame sensor, the intensity or surface brightness of the images formed on both sensors will be the same. We saw this at work in the above illustrations comparing exposures made with the D610 and D90. Despite the fact that, during each set of exposures, the D90’s smaller sensor collected less total light than the full frame sensor of the D610, the image made by the D90 was still properly exposed. This is because the exposures made by both cameras produced images having identical surface brightness at the image plane.

This set of images compares performance between crop sensor and full frame DSLR bodies. The images in the left column were made with a Nikon D90. Images in the right three columns were made with a Nikon D610. Both cameras used the same Tamron 70-200mm f/2.8 Di VC USD zoom lens, which was set up on a tripod to ensure it would not change position during the test. Both cameras used ISO 200, center point average metering and were operated in Aperture Priority. The subject in these photos is a scale model of the Lunar Excursion Module (LEM) from the Apollo program.

This set of images compares performance between crop sensor and full frame DSLR bodies. The images in the left column were made with a Nikon D90. Images in the right three columns were made with a Nikon D610. Both cameras used the same Tamron 70-200mm f/2.8 Di VC USD zoom lens, which was set up on a tripod to ensure it would not change position during the test. Both cameras used ISO 200, center point average metering and were operated in Aperture Priority. The subject in these photos is a scale model of the Lunar Excursion Module (LEM) from the Apollo program.

The above illustration allows us to compare the performance of crop sensor and full frame cameras. The first column of D610 exposures matches the settings of the D90 images in the left-most column. Focal length and focal ratio are the same. In most cases, both cameras’ metering systems selected the same exposure. The most obvious difference between the D90 and first set of D610 images is the wider angle of view delivered by the full frame sensor. For the second set of D610 images, I zoomed in to match the effective focal length of the D90. The angles of view of these images closely match the corresponding D90 exposures. The second set of D610 images were shot at f/2.8 and clearly display a more shallow depth of field. For the third set of D610 photographs, I changed the focal ratio to match the depth of field presented in the D90 images. Notice that the exposures for these images are all 1/800-second. They’re longer to compensate for the larger focal ratio.

Focal Ratio is the key to understanding how different cameras, lenses and sensors are able to make good photographs using the same or similar length exposures. Focal ratio determines the length of time needed to collect enough light to make an image having the required surface brightness. For any two cameras operating at the same ISO and delivering the same angle of view, the exposure times will typically be the same.

So, the next time you read or hear a photographer talking about an f/1.4 lens having a larger aperture than an f/2.0 lens, stop and give that statement some thought. If the lenses being compared are a 20mm f/1.4 and a 50mm f/2.0, the 50mm lens will be operating with a larger aperture. The 50mm lens will have a 25mm aperture at f/2.0 and the 20mm, f/1.4 lens aperture will be just over 14mm. However, due to its faster focal ratio, the 20mm lens will deliver more light per square millimeter to the sensor, faster. Because the f/1.4 lens produces a brighter image – an image having a higher surface brightness – the length of the exposure will be shorter.

In photography, the objective is not to deliver the largest volume of light to the sensor. The objective is to deliver the needed intensity (surface brightness) of light to the sensor. Speed is everything and focal ratio is the key.

Now, get out there and shoot!

Bill Ferris | August 2015